Set the pinned state to float if we can detect that no exception can arise
Set the pinned state to float if we can detect that no exception can arise

[r4151]

MatzeB/libfirm,davidgiven/libfirm,davidgiven/libfirm,davidgiven/libfirm,8l/libfirm,killbug2004/libfirm,jonashaag/libfirm,davidgiven/libfirm,MatzeB/libfirm,jonashaag/libfirm,8l/libfirm,jonashaag/libfirm,libfirm/libfirm,8l/libfirm,libfirm/libfirm,MatzeB/libfirm,killbug2004/libfirm,davidgiven/libfirm,8l/libfirm,killbug2004/libfirm,jonashaag/libfirm,MatzeB/libfirm,8l/libfirm,jonashaag/libfirm,libfirm/libfirm,libfirm/libfirm,MatzeB/libfirm,davidgiven/libfirm,killbug2004/libfirm,8l/libfirm,killbug2004/libfirm,8l/libfirm,libfirm/libfirm,jonashaag/libfirm,killbug2004/libfirm,MatzeB/libfirm,MatzeB/libfirm,davidgiven/libfirm,killbug2004/libfirm,jonashaag/libfirm